Halitosis, is breath that has an unpleasant odor. This odor can strike periodically or be persistent, depending on the cause. Halitosis is primarily caused by some of the bacteria forming the natural bacterial flora in the oral cavity, particularly bacteria located in the crypts at the back of the tongue and in periodontal pockets. Said bacteria produce by anaerobic metabolism volatile sulfur compounds which is mainly hydrogen sulfide and methyl mercaptan giving rise to the unpleasant odor.
It is well known in the art that zinc ions possess a certain antibacterial activity and to some extent reduce the volatile sulfur compounds production in the oral cavity. Antibacterial agents like e.g. chlorhexidine, cetylpyridinium chloride and also chitosan have been suggested and investigated in order to reduce the production of volatile sulfur compounds, and thereby diminish the unpleasant odor, and has been described in:
Young et al. (Eur J Oral Sci 2003; 111:400-404) discloses inhibition of orally produced volatile sulfur compounds by Zinc, chlorohexidine or cetylpyridinium chloride and the effect of the concentration.
Roldan et al. (J Clin Periodontol 2004; 31:1128-1134) discloses the comparative effects of different chlorhexidine mouth-rinse formulations on volatile sulphur compounds and salivary bacterial counts.
Verkaik et al. (J Dentistry 2011; 39:218-224) discloses the efficacy of natural antimicrobials in toothpaste formulations against oral biofilms in vitro.
NO 307168 discloses that an anti-volatile sulfur compounds effect of zinc ion is mainly directed against hydrogen sulfide production and to a far lesser extent against the production of methyl mercaptan which explain the incomplete elimination of the halitosis. However, when a combination of zinc ions and low concentration of certain cationic antibacterial agents were used the combination inhibited both hydrogen sulfide and methyl mercaptan formation in a synergistic way.
The microbial flora in the oral cavity is a fine-tuned protective system playing an important part in the immune system, and in decomposing the nutrition we eat, and is further responsible for keeping the digestion system in balance. A shift in this delicate system due to antibacterial activity from antibacterial agents may lead to fungus growth, soar mouth, diarrhea etc. Said agents may also cause dental stain.
In work leading up to this invention the inventor surprisingly detected that by combining an antibacterial agent in an amount insufficient to provide antibacterial effect together with a physiologically acceptable divalent metal ion in a very low concentration and a physiologically acceptable polymer, the composition reduces the sulfur gasses in a synergistic way without any interference with the microbial flora in the oral cavity. The composition was demonstrated to prevent and/or treat halitosis, bad breath, dry mouth or sore throat.
Zinc lozenges have been suggested as a cure for common cold (Eby III et al. Medical Hypotheses 2010; 74:482-92). This is still controversial and the zinc concentration used for this purpose is much higher than in the composition of the present invention and is likely to be caused by an antibacterial and/or antiviral effect. It is thus highly surprising and unexpected that the present invention where proved to be efficient against sore throat even though no apparent antibacterial effect is present. The mechanism for this is still unknown.
It is therefore believed that the present invention will be a safer and more effective composition in preventing and/or treating halitose, bad breath, dry mouth or sore throat.